Radiation therapy is used to treat cancerous tumors with ionizing radiation that kills the affected cancer cells. External beam radiotherapy can be used to deliver ionizing radiation. In such therapy, a patient is placed on a couch and a radiotherapy beam generator is positioned to direct the ionizing radiation at the patient's tumor.
A linear accelerator (“LINAC”) is typically used for the purpose of delivering external beam radiation treatments to patients. A LINAC can deliver high-energy x-ray beams to the region of the target tissue, where the x-ray is sufficiently focused to destroy the target cells (e.g., tumor cells, abnormal cells, etc.), while avoiding the surrounding normal tissue.